The Rockville plate. Relief from Copernicus GLO-30; rivers and lakes from USGS NHD; watersheds from the USGS Watershed Boundary Dataset; roads and city limits from Census TIGER 2024.
Mostly sunny
Mostly sunny; warmer
Partly cloudy
Partly cloudy
Mostly cloudy
Partly cloudy
Showers likely
70° on Nov. 13, 1999, the hottest reading for this week of the year since 1892. Next is 68° in 1953.
Rockville’s center stands about 1,090 ft above sea level. Within three miles the land runs from 1,060 ft to 1,280 ft, a difference of 220 ft: rolling country.
Under the town center the state geologic map shows Rockville Granite and rocks inferred to be related, from the Paleoproterozoic, 1.6 to 1.8 billion years old.
The section below crosses 6 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 53×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Granite. Age: Paleoproterozoic, 1.6 to 1.8 billion years old. About 12 mi of the line.
Granodiorite, granite. Age: Paleoproterozoic, 1.6 to 1.8 billion years old. About 5 mi of the line.
Conglomerate, sandstone, mudstone. Age: Late Cretaceous, 72 to 100 million years old. About 3 mi of the line.
Orthogneiss, schist. Age: Paleoproterozoic, 1.6 to 2.5 billion years old. About 2 mi of the line.
Gabbroic, dioritic. Age: Archean to Paleoproterozoic. About 1 mi of the line.
Age: Paleoproterozoic, 1.6 to 1.8 billion years old. About 0.7 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale.
Heights from Copernicus GLO-90 (a surface model: it includes buildings and tree canopy); summits from USGS GNIS; rivers from USGS NHDPlus HR; rock from the USGS State Geologic Map Compilation.
A raindrop that lands in Rockville reaches the Gulf of America by way of Mill Creek, the Sauk and the Mississippi: about 1,930 river miles.
Lake on the way: Lake Pepin.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Rockville; river miles along the main stem, rounded.
Rockville has a warm-summer humid continental climate. Summer afternoons average 81° in July; winter nights fall to about 4° in January. A normal year brings about 57 inches of snow; with the rain, that comes to about 31 inches of water.
On November 14 Rockville normally reaches 40° and falls to 25°. The record high is 67°, in 1990; the record low −4°, in 1919. The most rain on this date, 0.91 in, fell in 1909.
Normals 1991–2020 and records since 1892 at Collegeville St. John'S, 8 miles north-northwest, 120 ft higher. NOAA, through RCC-ACIS.
